The massive budget overrun of the Diamond Synchrotron wasn't STFC's fault, it was ultimately the fault of Tony Blair and partially down to Lord Sainsbury and the Wellcome Trust. It was the latter two that pushed for the machine to be built in Oxfordshire, rather than at Daresbury in Cheshire - which is where it was designed to be built. Blair personally made the final call as to where it was built.
Lo and behold, not only did they have to dig much, much deeper foundations in Oxfordshire before hitting solid rock, than they would have had to do at Daresbury - they also found a load of archeological rubbish which further delayed construction and increased cost. Add to this the fact that most of the UK's Synchrotron expertise was already based at Daresbury, and a lot of them decided they didn't want to move to Oxfordshire, and either took more lucrative jobs abroad, retired, or quit science altogether - and that's the biggest crime against UK Physics.